Breast cancer deaths are falling at 4 per cent a year in the North but remain static in the Republic, writes Dr Muiris Houston, Medical Correspondent.
Today's publication of the second in an ongoing series of reports on cancer statistics covering the whole of the island of Ireland offers some interesting insights.
At the outset, the added value of calculating incidence and death rates for cancer from North and South must be acknowledged. Not alone does it offer a more complete set of data, but it is a testimony to the ongoing co-operation between the two cancer registries, a task which has now become routine rather than exceptional. The crucial input of the National Cancer Institute in the US in putting together a tripartite consortium to improve cancer care in the Republic is also evident.
Of the 19,000 new cancer cases every year, the big four cancers continue to predominate. Colon cancer, lung cancer, tumours of the breast in women and prostate cancer in men are far more common than cancers at other sites in the body. They also account for about half of cancer-related deaths throughout the island.
While we cannot alter our age or genetic make up, there are modifiable risk factors for cancer. Approximately one-third of cancers are caused by tobacco; one-third by a diet high in fat and low in fruit and vegetables; and most of the remaining third by other lifestyle choices such as excessive drinking, a lack of regular exercise and frequent sunburn.
Colorectal cancer can be directly linked to diet and exercise. The eastern seaboard and the south have significantly more cases of this type of cancer, with the north midlands having the highest incidence of colon cancer. While the more urban environment in the east, with its accompanying pockets of deprivation and associated poor dietary habits, might explain some of the trend, it is by no means the whole story. This has been acknowledged by the director of the National Cancer Registry in the Republic, who will today call for funding to explore the reasons for geographic trends in colon cancer.
While the prostate cancer statistics might at first glance lead to concerns of an epidemic in the Republic, this is clearly not the case. Although the differences in rates between North and South are statistically different, there is a number of possible explanations. First, there is no internationally agreed process to screen for prostate cancer: although a blood test for prostate specific antigen (PSA) exists, its interpretation is less than straightforward. And while the level of PSA testing in both parts of the island is similar, it appears that more men in the Republic are being sent for surgical biopsy.
Doctors (and patients) in the North may be better at what is called "PSA watchful waiting", in which a marginally elevated PSA level is repeated several months later rather than acted on immediately.
There may also be a fault-line developing between the public-only health service in the North and the private/public service in the Republic. Is it possible that private patients in the South are accessing specialist biopsy procedures more frequently because of greater access to private medicine? These and other questions will hopefully be answered by a two-year research project into prostate cancer on which both registries will collaborate.
The difference in breast cancer incidence and deaths is more easily explained. By introducing breast screening for its entire population in 1993, Northern Ireland is now reaping the benefits. Deaths from breast cancer are falling at 4 per cent per annum in the North, with a cumulative 30 per cent drop in breast cancer deaths in the decade since screening began. In contrast, death from breast cancer remains static in the Republic, notwithstanding its partial introduction of breast screening in 2000.
In fairness, the Minister for Health has committed to the national extension of Breastcheck and has already provided funding for this. But women in the south and west might reasonably ask why some of the approximately €550 million invested in cancer services in the last four years has not resulted in a full nation-wide breast cancer screening programme.
The earlier such a service is up and running, the more Irish women will survive cancer. The statistics for breast screening are a classic example of how both health systems on the island can learn from one another.
The Republic has, of course, introduced a major health initiative which the North has not. The workplace ban on tobacco will cut smoking rates here. With such a close link between smoking and lung cancer, Michael Martin's move will begin to pay significant dividends in about 10 years.
Both parts of the island need to focus on getting the anti-smoking message through to those in lower socio-economic groups, whose smoking rates remain stubbornly high. The east/west divide in lung cancer rates, revealed so clearly in today's report, illustrates this point by highlighting pockets of disease in Dublin, Belfast and other urban centres.
This excellent report raises many questions about individual cancers. It has implications for issues as diverse as quality of care, healthcare resource utilisation and the structure of our health services. For it to reach its full potential its findings must be utilised at a level that improves the lot of the individual cancer patient.